1) An operating system is a set of programs that schedule tasks, allocates storage and presents a default interface to the user between applications.Many of the first operating systems were device-dependent and proprietary.

The functions of the operating systems are:

starting a computer

providing a user interface

managing data and programs

managing memory

configuring devices

2) A device-dependent program is the one that runs only on a specific make of a computer.

3) Proprietary software is privately owned and limited to a specific vendor or computer.

4) An operating system is a set of programs that coordinates all the activities among the computer hardware devices.In most cases, the operating system is installed and resides on the computer’s hard disk.

5) However, on handheld computers and many mobile devices such as PDAs and smart phones, the operating system may reside on a ROM chip.

6) The operating system that a computer uses sometimes is called the platform.

EXAMPLE OF OPERATING SYSTEM :

i) Linux is a freely distributed UNIX, it is a compatible operating system for PCs and a number of other processors.

ii) Mac OS X is a multitasking operating system that is the latest version of the Macintosh operating system.

iii) UNIX is an operating system, or family of operating systems, developed at Bell Laboratories in early 1970sas a replacement for an earlier system called Multics.

iv) Windows XP is the latest version of the Windows operating system, which is Microsoft’s fastest, most reliable Windows operating system.